1. Field of the Invention
The invention described herein relates to a grape harvesting head and more specifically to a harvesting head supported in a harvester framework, wherein the framework is driven over the ground along extended rows of vines carrying a crop supported by cordons spaced along the extended rows.
2. Description of the Prior Art
U.S. Pat. No. 4,341,062, Scudder, for a Coffee Harvester, describes an oscillation generating head for use in harvesting coffee beans from coffee bushes. Scudder's harvester travels alongside the coffee bushes and includes an array of tines extending horizontally from a vertically disposed shaft that is driven in an oscillatory fashion by the oscillation generating head. The oscillating shaft is allowed to rotate through 360′. The array of tines engages and travels past the coffee bushes.
U.S. Pat. No. 5,355,667, Scott, describes a single head grape and raisin harvester with a single oscillating shaker head that is said to center itself on a row of grape vines engaged by the harvester. The harvester is towed by a tractor and uses the shaker disclosed in the aforementioned Scudder '062 patent. The shaker drives a shaft in an oscillatory manner. A plurality of shaker tines extend radially from the shaft. The shaft is allowed to rotate through 360′ as the oscillating tines engage and are drawn past a row of grape vines by the tractor.
U.S. Pat. No. 5,813,910, Meester et al., also includes disclosure of an oscillating shaker head, wherein the oscillation is provided by an eccentric weight assembly similar to those described in the previously-mentioned '062 and '667 patents. The Neester et al. shaker is adjustable in oscillation amplitude while the apparatus is operating. The oscillation from the head is im parted to a brush having a plurality of rows of radially extending tines. The radially extending tines on the shaft form a shaker brush which is free to rotate through 360′.
U.S. Pat. No. 4,418,521, Orlando et al., discloses a harvester for grapes growing on tines having a force balance assembly imparting oscillation to groups of “beater rods” or tines that extend from their mounts rearwardly from the harvester. The tines are disposed to disturb the vines in an oscillatory fashion in a substantially horizontal plane. The “beater rods” are positioned to engage the vines on each side of the vine row.
There is a style of vine training for growing grapes that is referred to as cordon supported. One type of cordon supported training for grape vines is shown in FIG. 2 of the drawings, wherein a “V” shaped cross arm 11 has an upright support post 12 embedded in and extending from a ground surface. A plurality of support wires 13 extend between spaced ones of the “V” shaped supports so that crops, such as grape vines, may be grown and supported along the lengths of the wires 13. The “V” shaped cross arm is called a cordon. FIG. 3 shows an alternate form of support for a vine type plant, wherein the upright post 12 supports a straight cross arm 14. The cross arm 14 is also called a cordon and has a plurality of the wires 13 running along the length of a row of growing vine crop. The wires 13 are supported by spaced cordon assemblies, such as illustrated in FIG. 3.
The cordons divide the vine into two distinct fruiting areas, one on each side of the vine. In many instances, grape crops supported on cordon systems are difficult to harvest mechanically and must therefore be hand picked. Sometimes it is desirable to mechanically harvest crops grown on cordon systems, for example, when the grapes are not of high enough quality to be used for fresh fruit consumption. These grapes are called strippings. Hand harvesting of strippings, or grapes that are left over after hand picking, is not economically feasible. Mechanical harvesting of grapes grown on cordon systems has presented problems for current styles of picking mechanisms, which tend to shake the vine from side to side to effect fruit removal. Additionally, the cordon heights vary from row to row and field to field, which requires that current styles of picking mechanisms must be changed in height above the ground during mechanical picking operations to effectively harvest the fruit. Vineyards grown on cordon systems in rolling hills exhibit distances between the vines and the ground on opposite sides of the vine rows that may vary by up to forty inches. This variation of crop level above the ground in the same cordon supported vine row is the product of a number of circumstances, such as soil tilling, which causes the soil to shift downward on the hillside, creating a “bench” effect as soil is deposited from up the hill down toward the area under vine. In this fashion the downhill side of the vine row may become closer to the ground. Since it is desirable to maintain contact with the cordon on the side of the vine row being harvested, this unpredictable and ever-changing cordon height presents a problem for picking mechanisms which are not adjustable in height over the ground surface.